Corticospinal And Spinal Neuromuscular Function During Quadriceps Eccentrics And Isometrics After ACL-reconstruction: Case-control Preliminary Report: 1016
Authors: Akre, M.
Conference: ACSM
Dates: 26/05/2025
Publication Date: 01/10/2026
Abstract:PURPOSE: Anterior cruciate ligament reconstruction (ACLR) results in neuromuscular impairment that may increase reinjury risk. We examined corticospinal and spinal neuromuscular function during quadriceps eccentrics (E) and isometrics (I) in adults with (case) and without (control) unilateral ACLR. Transcranial magnetic stimulation (TMS) and peripheral nerve stimulation (PNS) were used to examine corticospinal and spinal function, respectively. We hypothesized there would be statistically significant differences for both muscle actions between cases’ operated and non-operated limbs and between cases’ operated limbs and controls’ dominant limbs. This preliminary report of ongoing case-control work is the first published study combining E and TMS measurement in adults with ACLR.
METHODS: Ten ACLR (28.4 ± 6.0 yr) and 10 healthy controls (25.3 ± 4.0 yr) participated. Data were collected with isokinetic E (0-60° flexion) and I (45° flexion) quadriceps actions. Variables included active motor threshold (AMT, %), maximal M wave (MMAX, mV), maximal voluntary effort (MVE, Nm/kg), central activation ratio (CAR, %), motor evoked potential (MEP), short interval cortical inhibition (SICI). Normality was assessed with Shapiro Wilk tests. Wilcoxon signed rank and Mann Whitney U tests were used, Bonferroni corrected alpha = 0.004.
RESULTS: Operated limb medians/interquartile ranges (IQR) were AMT, 40.5/11; MMAX, 3.3/2.2; MVE, E 2.3/0.6, I 2.1/1.1; CAR, 80.4/12.5; MEP, E 0.3/0.2, I 0.3/0.2; SICI, E 0.6/0.6, I 0.8/0.7. Non-operated limb medians/IQRs were AMT, 39.5/7.5; MMAX, 4/2.2; MVE, E 2.2/0.7, I 2.2/0.9; CAR, 81.3/4.9; MEP, E 0.3/0.3, I 0.3/0.1; SICI, E 0.9/0.4, I 1.1/0.1. Dominant limb medians/IQRs were AMT, 35/3; MMAX, 4.1/1.1; MVE, E 3.2/0.7, I 2.8/0.8; CAR, 85.1/5.3; MEP, E 0.4/0.2, I 0.5/0.1; SICI, E 0.6/1.1, I 1.6/0.8. Most comparisons were non-significant (p > 0.020). Operated-nonoperated limb comparisons, only I MVE was significant (p = 0.001). Case-control comparisons, only E MVE was significant (p < 0.001).
CONCLUSION: Data show E and I quadriceps MVE deficits after ACLR, being concurrent with comparable within-group and between-group corticospinal and spinal measures. Isokinetic E assessment appears useful to identify quadriceps neuromuscular impairment between cases and controls.
Source: Manual